1. Field of the Invention
The present invention relates to an operation speed change system and method for a refrigerator, and more particularly to, in the driving of a compressor of an inverter refrigerator an operation speed of which is variable, an operation speed change system and method for a refrigerator that improves power consumption of the refrigerator by varying an operation frequency of the refrigerator by sensing the change of a temperature inside the refrigerator in accordance with various conditions such as a fast mode selection by a user, the temperature change outside the refrigerator and the closing/opening of the refrigerator.
2. Description of the Conventional Art
FIG. 1 is a schematic diagram of a general refrigerator. As shown therein, the refrigerator includes a compressor 13 supplying a gaseous refrigerant with high temperature and pressure, an evaporator 11 cooling down a freezer 20 and a cold-storage room 30 through a heat exchange with peripheral units by evaporating the refrigerant supplied from the compressor 13 which becomes a liquid state at low temperature and pressure while passing through a condenser (not shown) and a capillary (not shown), a damper 12 controlling a temperature inside the cold-storage room 30 by supplying or excluding cool air come from the freezer 20 to the cold-storage room 30, and a freeze fan motor 10 driving a freeze fan 14 which forcibly sends the cool air to the freezer 20 as the process of cool air circulation.
Now, the operation of the refrigerator will be described with reference to FIG. 1.
When power is supplied, the compressor 13 compresses the gaseous refrigerant to have high temperature and pressure and the compressed refrigerant is supplied to the evaporator 11 through the condenser and the capillary. The evaporator 11 evaporates the refrigerant which has become the liquid state with low temperature and pressure while passing through the condenser and the capillary from the compressor 13, thereby supplying the refrigerant to the freezer 20 and the cold-storage room 30 through the heat exchange with the peripheral units to cool down the interior of the refrigerator.
The damper 12 controls the temperature of the cold-storage room 30 by supplying or excluding the cool air provided from the freezer 20, and the freeze fan motor 10 drives the freeze fan 14 to supply the cool air produced from the evaporator 11 to the freezer 20, whereby the cool air circulation occurs. In addition, in the driving of the compressor, an operation frequency is uniformly fixed (generally, fixed at 60 Hz) and when the temperature inside the refrigerator becomes higher than a predetermined temperature, the compressor starts operating and then suspends its operation when reaching the predetermined temperature.
In the conventional art, however, there is problem in that since the operation frequency of the compressor is uniformly fixed, generally, at 60 Hz, it is impossible to achieve a flexible operation of the compressor in accordance with the change of the interior conditions of the refrigerator.
For instance, when food is placed in the refrigerator by opening a door thereof and when the temperature inside the refrigerator increases because the load of the food is large, the temperature inside the refrigerator must be decreased to an appropriate level by rapidly driving the compressor. However, since the operation frequency is fixed, it is difficult to cope with the temperature change within the limited time, which results in a loss of its freshness. Contrarily, although the food with a small load is placed in the refrigerator, the compressor is driven with the operation frequency which is higher than an actually required frequency, whereby an energy is unnecessarily consumed.